diff: vary default prefix depending on what are compared
With a new configuration "diff.mnemonicprefix", "git diff" shows the differences between various combinations of preimage and postimage trees with prefixes different from the standard "a/" and "b/". Hopefully this will make the distinction stand out for some people. "git diff" compares the (i)ndex and the (w)ork tree; "git diff HEAD" compares a (c)ommit and the (w)ork tree; "git diff --cached" compares a (c)ommit and the (i)ndex; "git-diff HEAD:file1 file2" compares an (o)bject and a (w)ork tree entity; "git diff --no-index a b" compares two non-git things (1) and (2). Because these mnemonics now have meanings, they are swapped when reverse diff is in effect and this feature is enabled. Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano committed
Aug 18, 2008 at 20:08 UTC
a5a818ee4877e4458e8e6741a03ac3b19941d58a
7 files changed
+70
-8
Documentation/config.txt
+16
@@ -581,6 +581,22 @@ diff.external::
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you want to use an external diff program only on a subset of
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your files, you might want to use linkgit:gitattributes[5] instead.
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+diff.mnemonicprefix::
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+ If set, 'git-diff' uses a prefix pair that is different from the
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+ standard "a/" and "b/" depending on what is being compared. When
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+ this configuration is in effect, reverse diff output also swaps
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+ the order of the prefixes:
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+'git-diff';;
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+ compares the (i)ndex and the (w)ork tree;
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+'git-diff HEAD';;
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+ compares a (c)ommit and the (w)ork tree;
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+'git diff --cached';;
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+ compares a (c)ommit and the (i)ndex;
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+'git-diff HEAD:file1 file2';;
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+ compares an (o)bject and a (w)ork tree entity;
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+'git diff --no-index a b';;
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+ compares two non-git things (1) and (2).
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+
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diff.renameLimit::
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The number of files to consider when performing the copy/rename
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detection; equivalent to the 'git-diff' option '-l'.
builtin-diff.c
+2
@@ -74,6 +74,8 @@ static int builtin_diff_b_f(struct rev_info *revs,
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if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
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die("'%s': not a regular file or symlink", path);
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+ diff_set_mnemonic_prefix(&revs->diffopt, "o/", "w/");
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+
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if (blob[0].mode == S_IFINVALID)
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blob[0].mode = canon_mode(st.st_mode);
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combine-diff.c
+6
-2
@@ -675,9 +675,13 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
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int i, show_hunks;
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int working_tree_file = is_null_sha1(elem->sha1);
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int abbrev = DIFF_OPT_TST(opt, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
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+ const char *a_prefix, *b_prefix;
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mmfile_t result_file;
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context = opt->context;
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+ a_prefix = opt->a_prefix ? opt->a_prefix : "a/";
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+ b_prefix = opt->b_prefix ? opt->b_prefix : "b/";
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+
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/* Read the result of merge first */
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if (!working_tree_file)
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result = grab_blob(elem->sha1, &result_size);
@@ -853,13 +857,13 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
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dump_quoted_path("--- ", "", "/dev/null",
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c_meta, c_reset);
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else
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- dump_quoted_path("--- ", opt->a_prefix, elem->path,
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+ dump_quoted_path("--- ", a_prefix, elem->path,
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c_meta, c_reset);
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if (deleted)
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dump_quoted_path("+++ ", "", "/dev/null",
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c_meta, c_reset);
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else
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- dump_quoted_path("+++ ", opt->b_prefix, elem->path,
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+ dump_quoted_path("+++ ", b_prefix, elem->path,
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c_meta, c_reset);
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dump_sline(sline, cnt, num_parent,
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DIFF_OPT_TST(opt, COLOR_DIFF));
diff-lib.c
+3
@@ -63,6 +63,8 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
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? CE_MATCH_RACY_IS_DIRTY : 0);
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char symcache[PATH_MAX];
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+ diff_set_mnemonic_prefix(&revs->diffopt, "i/", "w/");
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+
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if (diff_unmerged_stage < 0)
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diff_unmerged_stage = 2;
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entries = active_nr;
@@ -469,6 +471,7 @@ int run_diff_index(struct rev_info *revs, int cached)
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if (unpack_trees(1, &t, &opts))
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exit(128);
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+ diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
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diffcore_std(&revs->diffopt);
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diff_flush(&revs->diffopt);
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return 0;
diff-no-index.c
+1
@@ -252,6 +252,7 @@ void diff_no_index(struct rev_info *revs,
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if (queue_diff(&revs->diffopt, revs->diffopt.paths[0],
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revs->diffopt.paths[1]))
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exit(1);
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+ diff_set_mnemonic_prefix(&revs->diffopt, "1/", "2/");
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diffcore_std(&revs->diffopt);
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diff_flush(&revs->diffopt);
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diff.c
+40
-6
@@ -23,6 +23,7 @@ static int diff_rename_limit_default = 200;
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int diff_use_color_default = -1;
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static const char *external_diff_cmd_cfg;
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int diff_auto_refresh_index = 1;
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+static int diff_mnemonic_prefix;
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static char diff_colors[][COLOR_MAXLEN] = {
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"\033[m", /* reset */
@@ -149,6 +150,10 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
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diff_auto_refresh_index = git_config_bool(var, value);
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return 0;
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}
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+ if (!strcmp(var, "diff.mnemonicprefix")) {
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+ diff_mnemonic_prefix = git_config_bool(var, value);
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+ return 0;
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+ }
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if (!strcmp(var, "diff.external"))
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return git_config_string(&external_diff_cmd_cfg, var, value);
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if (!prefixcmp(var, "diff.")) {
@@ -305,6 +310,15 @@ static void emit_rewrite_diff(const char *name_a,
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const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
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const char *reset = diff_get_color(color_diff, DIFF_RESET);
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static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
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+ const char *a_prefix, *b_prefix;
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+
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+ if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
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+ a_prefix = o->b_prefix;
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+ b_prefix = o->a_prefix;
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+ } else {
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+ a_prefix = o->a_prefix;
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+ b_prefix = o->b_prefix;
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+ }
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name_a += (*name_a == '/');
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name_b += (*name_b == '/');
@@ -313,8 +327,8 @@ static void emit_rewrite_diff(const char *name_a,
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strbuf_reset(&a_name);
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strbuf_reset(&b_name);
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- quote_two_c_style(&a_name, o->a_prefix, name_a, 0);
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- quote_two_c_style(&b_name, o->b_prefix, name_b, 0);
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+ quote_two_c_style(&a_name, a_prefix, name_a, 0);
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+ quote_two_c_style(&b_name, b_prefix, name_b, 0);
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diff_populate_filespec(one, 0);
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diff_populate_filespec(two, 0);
@@ -1432,6 +1446,14 @@ static const char *diff_funcname_pattern(struct diff_filespec *one)
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return NULL;
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}
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+void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
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+{
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+ if (!options->a_prefix)
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+ options->a_prefix = a;
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+ if (!options->b_prefix)
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+ options->b_prefix = b;
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+}
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+
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static void builtin_diff(const char *name_a,
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const char *name_b,
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struct diff_filespec *one,
@@ -1445,9 +1467,19 @@ static void builtin_diff(const char *name_a,
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char *a_one, *b_two;
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const char *set = diff_get_color_opt(o, DIFF_METAINFO);
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const char *reset = diff_get_color_opt(o, DIFF_RESET);
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+ const char *a_prefix, *b_prefix;
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+
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+ diff_set_mnemonic_prefix(o, "a/", "b/");
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+ if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
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+ a_prefix = o->b_prefix;
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+ b_prefix = o->a_prefix;
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+ } else {
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+ a_prefix = o->a_prefix;
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+ b_prefix = o->b_prefix;
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+ }
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- a_one = quote_two(o->a_prefix, name_a + (*name_a == '/'));
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- b_two = quote_two(o->b_prefix, name_b + (*name_b == '/'));
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+ a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
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+ b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
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lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
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lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
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fprintf(o->file, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
@@ -2308,8 +2340,10 @@ void diff_setup(struct diff_options *options)
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DIFF_OPT_CLR(options, COLOR_DIFF);
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options->detect_rename = diff_detect_rename_default;
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- options->a_prefix = "a/";
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- options->b_prefix = "b/";
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+ if (!diff_mnemonic_prefix) {
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+ options->a_prefix = "a/";
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+ options->b_prefix = "b/";
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+ }
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}
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int diff_setup_done(struct diff_options *options)
diff.h
+2
@@ -160,6 +160,8 @@ extern void diff_tree_combined(const unsigned char *sha1, const unsigned char pa
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extern void diff_tree_combined_merge(const unsigned char *sha1, int, struct rev_info *);
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+void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b);
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+
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extern void diff_addremove(struct diff_options *,
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int addremove,
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unsigned mode,